How can a router be configured to disable OSPF authentication?

Disabling OSPF authentication is achieved by removing the OSPF authentication configuration from an interface or OSPF process. The command "no ip ospf authentication" directly turns off any authentication that has been previously set for OSPF on an interface. This means that the OSPF routers will no longer require authentication to form neighbor relationships.

It is important to configure OSPF correctly, particularly in production networks, to ensure that routing updates are secure. By using this specific command, you eliminate the requirement for OSPF authentication, which could help in situations where authentication is not desired or not feasible.

The other choices do not utilize the correct syntax or structures for OSPF configuration. Understanding the correct command syntax is crucial, as even slight variations can lead to desired configurations not being applied effectively. Using “no ip ospf authentication” is clear and directly conveys the action of disabling OSPF authentication.